The RH bank of injectors is tilted down slightly - more in the interests of a smoother pipe run than anything else. It would be fairly easy to tilt them both a little more downwards if this is likely to help, without suffering too much with injector wear?

mm, I forget these ones exit out the side. Just need to compromise between tipping the outlets down so that any oil runs out, and keeping upright to minimise plunger wear. I should think only a little angle is needed to stop oil pooling anywhere vital and risking cold waxing.

Thanks for that, I think I understand my problem with the changeover now as well. I'm a little embarrassed to admit it, but I thought the auto calibration was all you needed to do - so didn't take the laptop out on the road and map it properly

Got an inverter to power the laptop with (dead battery) and had a look at what it was doing in real time. It was running too lean until the petrol ECU sorted things out, so after adjusting things to get the petrol injection times similar at different speeds/loads things are a lot better all over the rev range. Might still have some fine tuning to do - I don't know how close you're aiming to get them. Petrol injection times are generally within 0.1ms regardless of fuel at the areas I've adjusted. Not done 4k rpm and above though yet.

Sometimes it does all work out of the box, but usually manual tickling is required. Target is to get the times as close as you can, 0.1mS sounds good enough. When you are able to observe OBD trim values on the car's own management it gets easier than estimating average pulse widths.Testing under high load/rpm is often tricky due to lack of suitable test track - a nice hill helps!At full throttle, the car won't be running closed loop so you can't compare times - under these conditions it is supposed to run rich, so you should at least see that the LPG stays rich at full throttle all the way to the redline, by lambda observation.

Testing under high load/rpm is often tricky due to lack of suitable test track - a nice hill helps!

Plenty of hills around here (North Wales), but also plenty of corners, slow cars and tractors. The plan is to hook up a trailer to give more load at achievable speeds. Then once it's in the open loop area of the map, increase the correction factor until it's just on the rich side (or decrease till lean, then richen up a touch).

Makes me think back to playing with carb jets and needles, although considerably easier to make the adjustments and see the results!

OK, so it's nothing to do with gas, but I thought I'd post up some photos of what I've been spending this weekend doing! (Not helped when my welder decided to pack up a couple of hours into starting the job, and the nearest one for hire was an 80 mile round trip away...)

Not in my view, unless you have a gas leak! In which case my priority would be sorting out the leak before doing any welding...

Just one point to make - I was doing some welding on the Discovery when it had the original LPG system installed. I disconnected the battery and the LPG ECU earth connection to the battery; however there was (unknown to me) an additional ECU earth to the bodywork. Although this was well away from the welded area my ECU failed straight after welding. I've never disconnected ECUs before and been fine, but problems can happen!

Do you need to take any extra precautions before welding on an LPG powered car?

As usual, it depends on what you are welding.

From a safety point of view, you need to protect all pipes, tanks, fittings, etc from heat. So if your welding goes near a tank then you'd need to either shield the tank or remove it. And as Mat says, you really don't want to be welding if there's any leaks. Really, it's not much different to the precautions you'd want to take with the petrol system.

mat_fenwick wrote:

Just one point to make - I was doing some welding on the Discovery when it had the original LPG system installed. I disconnected the battery and the LPG ECU earth connection to the battery; however there was (unknown to me) an additional ECU earth to the bodywork. Although this was well away from the welded area my ECU failed straight after welding. I've never disconnected ECUs before and been fine, but problems can happen!

Personally I don't disconnect the battery. I know it's a bit of a hot topic for debate, but I tend to take the approach that the battery is a great absorber of surges - that's why you really shouldn't run a vehicle with it disconnected. So if you leave it connected, then anything permanently live will have this "dump" attached which will help to deal with any induced surges. Anything that's switched (ie not live with the key off) will be no better or worse with the battery disconnected.

At one time, advice was to disconnect the alternator. Back then the alternator (and in particular it's rectifier) was the only bit of electronics in most cars. Now there are just so many black boxes that it's impossible to disconnect them all.

There are two issues of interest.

Firstly, there are ground potential differences. If you have two bits of equipment, both connected to the bodywork, and with a connection between then, then as you weld, there will be voltage differences between different bits of bodywork - which appear at the equipment as unusual voltages from the other equipment. Eg, if you managed to create (say) +10V difference at one point, equipment using that as an "earth" may see signals from other equipment at -10V. Equipment should be designed to cope with that, but there are limits - and some designers seem to have a cosy view of a nice clean electrical environment.Depending on circumstances, it may well be possible to get significantly higher voltage differences.You can minimise this effect by getting your earth clamp as close (electrically) to the job as you can. You will only create voltage differences where you get current to flow, so if you earth close to the weld site, the rest of the vehicle should be unaffected.

Secondly, there are induced spikes. Any wire carrying a current (such as your welder cables) will act as a transmitting antenna. Any other wire will act as a receiving antenna, such as those connected to all your little black boxes. Disconnecting the battery won't help with this either. In fact, disconnecting the battery will make things worse since (as already mentioned) the battery will sink some of the induced currents.

I know there are a couple of Landy fans on this board, so I thought I'd share my recent trials and tribulations! I've been doing a spot more welding on the old bus recently - it started off with a quick patch needed to the rear wheel arch

then I realised that it was pretty crusty all the way along, and so was the sill

and bottom of the C pillar

So all removed and cut back to good metal

Sill patched up with some pieces of galvanised sheet...

...and new wheel arch welded in place.

Final coat of paint was last night - it looks slightly better than the photo but not perfect by any means!

I still need to take off the sill cover on the other side, as I fear there is some rot behind that - the wheel arch at least is a lot better but after seeing what can be hidden behind the plastic I'd rather deal with it now before it gets worse!

And in something slightly LPG related I've got a copy of RoverGauge software, and connecting it to the 14CUX ECU. As it shows the long and short fuel trims it will enable me to set up the LPG map (hopefully) perfectly (I found it quite tricky switching between fuels and getting the petrol times the same whilst in real world road conditions).

Never realised the Disco was as similar to the RR Classic as that. Had rot in exactly the same places on the LSE. If the sills are only rotten on the outside so covered up by the plastic covers, it'll still go through the MoT but they usually fail as the wheelarch is right next to the seat belt mounting so an instant fail. In theory the sills wouldn't be a fail as they have a separate chassis, unfortunately rot within 30cm of a body mounting point is a fail too.

As far as I know they're almost identical under the skin, although the RR gets softer springs with the self levelling unit. I slightly prefer the RR shape though. TBH I'm not bothered about just getting it through the MOT - I'd rather it be solid even if it's not an MOT fail.

I've had a quick tug at the sill covers the other side, and they still seem well attached although there are signs of rust underneath. If it's thinned the meal significantly I'll cut it out too. At least I've already done the C pillar/seat belt mount on the other side!

...I had a little 'accident'. I was angle grinding next to a battery that I had inadvertently left on charge. Next thing I knew there was an almighty bang, a flash, and my face started to sting. This is what was left of the battery, and fortunately the stinging was only brief and minor...

I had one blow up in my face once too. It blew itself to pieces even more than yours did! It was my own fault for connecting a battery up the wrong way to the jumps leads (I was exhausted at the time and barely awake. Thats my excuse and I'm sticking to it).The bang was so loud, both me and my brother could not hear properly for hours. He got most of his hearing back a day or two later. I got an enormous lump on the forehead from a flying piece of plastic shrapnel. We both got acid on us but it was washed off quickly and we suffered no long-term damage. His neighbours thought there had been a gas explosion and were looking out their window for fire damage. All I could hear at the time was eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee!Luckily I could read lips and was able to calm my now hysterical wife and an over-concerned brother (who can also read lips) down. It was bloody hilarious, especially because all that was left of his battery was a plastic base and a load of lead plates.

Is near enough IS a RRC with different upper body. Chassis, running gear, floor pan, and lower bodywork is the same. This was Land Rover's "make or break" vehicle - they'd been starved of cash for years under British Leyland, everything was getting "stale", their traditional markets were being eaten up by the Japanese 4x4s. The Disco was done on a shoestring (they didn't have any money), and they were desperate to build something that would fit in the segment below their 'upmarket' RR, but above their utility vehicles - ie the market that was rapidly being owned by the Japanese.The main differentiator between Disco and RR was that the Disco had "older" engine options. IIRC the RR already had EFI and twin pipe manifolds - the first Disco V8s still had carbs and single pipe manifolds. The RR went 3.9, the Disco stayed 3.5 for a bit, and so on.

My Disco was a very early 2 door V8. Really nice car (much better than a RR IMO - especially for rear seat passengers). It had to go because I didn't have the skills or facilities to deal with the sort of issues above. The boot floor was rotten, rear door frame was well on it's way, Wheel arches and cills were going, and the inner wings were starting to show problems. I love the 110, but it's not a patch on the Disco for comfort - but at least most rot problems (like the doors) are "bolt on" repairs.

The main differentiator between Disco and RR was that the Disco had "older" engine options.

Yes, I never worked that out. Why did the Disco still have the old Lucas 14CUX ignition system with a distributor long after the Rangie had the GEMS engine? I don't think the Disco ever got the GEMS engine but went straight to the Thor. Then again, nothing surprises me with Land Rover. Why did they bring out the soft dash Range Rover Classic in late '93 when the P38 was due out barely a year later? Why are there 6 different door locks for a '93 Classic? Then again, they aren't alone. Why is it that many French cars can have a choice of 3 different brake calipers, and hence 3 different designs of brake pads, from 3 different manufacturers?

Why did the Disco still have the old Lucas 14CUX ignition system with a distributor long after the Rangie had the GEMS engine?

Sometimes it is due to product development, but a lot of the time when manufacturers do something like that it is due to an excess of old stock they need to get rid of or new stock they cannot get yet. So they use parts bin specials for a while until they've run out. It saves them money. Sometimes if a model is not selling well they will also "spec it up" by adding a padded dashboard or other slightly flashier interior or exterior mods. Streamlined bumper, new shape mirrors etc. Its all just a way to save money or make more money.

I have a friend who used to work for TVR years ago. He tells me they did it all the time there. They'd have a shortage of parts for the specific model due to unpaid bills or something similar so they'd have a car nearly ready to sell but not exhaust manifold to stick on it. So they'd fit one from a different model and modify the exhaust to fit.The classic bodge that came undone was the window shortage for one of their models. They had a row of cars all finished but unable to sell due to not having any door windows. So some bright spark suggested that they get a grinder and cut down to size a load of old stock from a previous model. This they did, and the cars were sent off to the dealers to be sold. A short while later several dealers were reporting complaints from customers about spontaneously shattering windows. One dealer had it happen in his showroom! No-one was even near the car at the time, when there was a sudden bang and the window shattered into tiny pieces. The toughened glass was obviously not as tough once it had been once shortened by someone in the factory with an angle grinder. This was typical.

Another one was where they had to make the wrong exhaust manifold fit to an exhaust that was too short. Instead of adding a short length to the exhaust they just bolted it all together regardless. Cue customers complaining of their exhaust falling off when they accellerated hard!

Not all manufacturers are quite as slapdash as that, but they all do it to a certain extent.

Last edited by sportston on Mon Nov 19, 2012 1:25 am, edited 3 times in total.

Why did the Disco still have the old Lucas 14CUX ignition system with a distributor long after the Rangie had the GEMS engine?

Simple marketing differentiation. The RR was deliberately pitched more up-market than Disco, and price-tagged to match. The RR gets 'advanced', the Disco gets 'adequate', it matters not the engines probably cost the same to manufacture.

Gilbertd wrote:

Why did they bring out the soft dash Range Rover Classic in late '93 when the P38 was due out barely a year later?

Product and market validation with the other new goodies destined for P38 i.e. air suspension et al

Gilbertd wrote:

Why are there 6 different door locks for a '93 Classic?

Production expediency ; what's cheap or actually available from suppliers this month, what new rules have the Californians introduced, what field issues have been resolved by redesign, what improvements are needed for next year's brochure ...

Oh I forgot another example was TVR supplying the German market with a "special" model of wheels. It was marketed as an "only for the German market" special edition. Truth was, they had a load of wheels they didn't need or want. They'd been ordered for a particular model but Peter Wheeler didn't like them when he saw them in the flesh so he chose a different model of wheel. So they sat in a corner of the warehouse unused. Some bright spark suggested they use them. So they stuck them on the cars for the German market just to get rid of them. When Peter saw the cars with them on he complained that they looked ugly, but when his sales manager told him that they were "only for the krauts Peter". He said, "Oh. Well thats alright then!" He wasn't too keen on germans (I don't know why. Maybe it was something to do with the second world war?) so he didn't mind them having crappy wheels. Lol.

Of course that all a long time ago now. Sadly Peter Wheeler is no more and neither is the TVR company. Shame, because despite TVRs having the odd quality control problem, they were great fun cars to drive and usually very quick and Peter was by all accounts quite a character.

Production expediency ; what's cheap or actually available from suppliers this month, what new rules have the Californians introduced, what field issues have been resolved by redesign, what improvements are needed for next year's brochure ...

Exactly. In another field, a friend of mine used to work for "a large global manufacturer" with a blue badge. On one occasion the cars were coming off the production line slightly overweight - so they upgraded the spec to alloy wheels to shed a few pounds.

Incidentally, my friend also told me he had problems with his car insurance for a while - apparently, when you have to reveal that you've written off "a few" cars in the last year, the insurers get a bit twitchy. When the manufacturer scraps a development car it has to go down against someone's name, and due to his position the finger pointed at him. And "a few" turned out to be a thousand one year when they were having a clear out. I'd love to have listened in on those conversations with potential insurers

Incidentally, my friend also told me he had problems with his car insurance for a while - apparently, when you have to reveal that you've written off "a few" cars in the last year, the insurers get a bit twitchy. When the manufacturer scraps a development car it has to go down against someone's name, and due to his position the finger pointed at him. And "a few" turned out to be a thousand one year when they were having a clear out. I'd love to have listened in on those conversations with potential insurers

It's now back on the road, and I took it over to Classicswede today to have someone more experienced cast their eye over the LPG set up. With a little more knowledge I'd gained since the install I begun to suspect that the nozzles might be a little too small, and I never really was 100% satisfied with the mapping I'd done at the top end, as it was difficult to get a clear run where we live.

The dual carriageway near his workshop was ideal for setting it up, and looking at the map with hindsight it seems I was just looking at each point in the table on its own, and not the map as a whole - there were big jumps in multipliers, and other areas which weren't quite right. I also didn't realise that the petrol injectors fired twice per cycle, and the gas ones only once! We ended up taking out the nozzles completely, and still had acceptable gas injector times.

Big thanks to Dai for the assistance and advice - although previously there was no detectable difference when changing between fuels I think now the throttle response is slightly crisper on gas, and it pulls harder at full throttle. A thoroughly nice bloke too!

Might have a lambda sensor problem though, as one of them flicked over 1 volt at times (with a larger LTFT on that bank), and both stayed at 0 volts for a detectable period of time. I'm trying to find out for certain what kind of sensors are fitted - I'm sure I've read somewhere they're 0-1 V inverted, as 'normal' sensors would have suffered from the effects of wading.

Oxygen Sensors were an invention of Volvo Car Corporation in the mid 1970's. The sensing element that Volvo pioneered consisted of a "zirconia" (zirconium oxide) ceramic bulb coated with a thin layer of platinum. Over ninety-five percent of all cars that use Oxygen Sensors use zirconia, but the Rover 14CUX system DOESN'T use zirconia sensors! Instead, it uses "titania" (titanium dioxide) sensors. Although they're technically more accurate and faster reacting, titania sensors carry a premium price. Many Nissan's and some Toyota's have also been equipped with titania sensors.

Zirconia Oxygen Sensors provide a fluctuating voltage output between 0.50V and 1.00V. Titania sensors don't create a voltage signal - instead they provide a resistance signal between about 20 kilohm (for a lean mixture) and about 1 kilohm (for a rich mixture). The Rover 14CUX ECU provides the sensors a low-current 5 volt supply and measures the resulting voltage drop across the sensors. So, if you measure DC voltage across the Oxygen Sensors while the vehicle is running (by connecting a voltmeter between terminal 4 and terminals 23 and 24 respectively) you should expect to see voltage readings that vary between 0.50V and 1.00V. Very interestingly, the voltage reading will look similar to what you'd see with zirconia Oxygen Sensors. There's a subtle difference, however. On a Rover 14CUX vehicle, a 0 volt reading means "lean" and a 1 volt reading means "rich", which is the reverse of what you'd expect on most other vehicles.

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